@Test
public void get() throws Exception {
// vv MapFileSeekTest
Text value = new Text();
reader.get(new IntWritable(496), value);
assertThat(value.toString(), is("One, two, buckle my shoe"));
// ^^ MapFileSeekTest
}
public static void printComparisonList(JobConf job, FileSystem hdfs) throws IOException {
MapFile.Reader partCompListReader =
new MapFile.Reader(hdfs, partitionComparisonList.getName(), job);
Text part = new Text();
TextArrayWritable array = new TextArrayWritable();
partCompListReader.get(part, array);
System.out.println(part.toString() + " neighbors: ");
for (int i = 0; i < array.get().length; i++) System.out.print(array.get()[i] + ", ");
}
@Test
public void testInvertedIndexing() throws Exception {
Configuration conf = new Configuration();
FileSystem fs = FileSystem.get(conf);
assertTrue(fs.exists(collectionPath));
String[] args =
new String[] {
"hadoop jar",
IntegrationUtils.getJar("dist", "cloud9"),
edu.umd.cloud9.example.ir.BuildInvertedIndex.class.getCanonicalName(),
IntegrationUtils.LOCAL_ARGS,
"-libjars=" + IntegrationUtils.getJar("lib", "guava"),
"-input",
collectionPath.toString(),
"-output",
tmpPrefix,
"-numReducers",
"1"
};
IntegrationUtils.exec(Joiner.on(" ").join(args));
MapFile.Reader reader = new MapFile.Reader(new Path(tmpPrefix + "/part-r-00000"), conf);
Text key = new Text();
PairOfWritables<IntWritable, ArrayListWritable<PairOfInts>> value =
new PairOfWritables<IntWritable, ArrayListWritable<PairOfInts>>();
key.set("gold");
reader.get(key, value);
assertEquals(584, value.getLeftElement().get());
ArrayListWritable<PairOfInts> postings = value.getRightElement();
assertEquals(584, value.getLeftElement().get());
assertEquals(5303, postings.get(0).getLeftElement());
assertEquals(684030, postings.get(100).getLeftElement());
assertEquals(1634312, postings.get(200).getLeftElement());
reader.close();
}
@Override
public void map(LongWritable key, Text value, Context context)
throws IOException, InterruptedException {
context.getCounter(MYCOUNTER.RECORD_COUNT).increment(1);
if (value.toString().length() > 0) {
String arrEmpAttributes[] = value.toString().split("\\t");
txtMapLookupKey.set(arrEmpAttributes[6].toString());
try {
// txtMapLookupKey = deptNo
// txtMapLookupValue = deptName
deptMapReader.get(txtMapLookupKey, txtMapLookupValue);
} finally {
txtMapLookupValue.set(
(txtMapLookupValue.equals(null) || txtMapLookupValue.equals(""))
? "NOT-FOUND"
: txtMapLookupValue.toString());
}
txtMapOutputKey.set(arrEmpAttributes[0].toString()); // empNo --> joinKey
txtMapOutputValue.set(
arrEmpAttributes[1].toString()
+ "\t"
+ arrEmpAttributes[1].toString()
+ "\t"
+ arrEmpAttributes[2].toString()
+ "\t"
+ arrEmpAttributes[3].toString()
+ "\t"
+ arrEmpAttributes[4].toString()
+ "\t"
+ arrEmpAttributes[5].toString()
+ "\t"
+ arrEmpAttributes[6].toString()
+ "\t" // deptNo
+ txtMapLookupValue.toString()); // deptName
}
context.write(txtMapOutputKey, txtMapOutputValue);
txtMapLookupValue.set("");
txtMapLookupKey.set("");
}
/** Runs this tool. */
@SuppressWarnings({"static-access"})
public int run(String[] args) throws Exception {
Options options = new Options();
options.addOption(
OptionBuilder.withArgName("path").hasArg().withDescription("input path").create(INDEX));
options.addOption(
OptionBuilder.withArgName("path")
.hasArg()
.withDescription("output path")
.create(COLLECTION));
CommandLine cmdline = null;
CommandLineParser parser = new GnuParser();
try {
cmdline = parser.parse(options, args);
} catch (ParseException exp) {
System.err.println("Error parsing command line: " + exp.getMessage());
System.exit(-1);
}
if (!cmdline.hasOption(INDEX) || !cmdline.hasOption(COLLECTION)) {
System.out.println("args: " + Arrays.toString(args));
HelpFormatter formatter = new HelpFormatter();
formatter.setWidth(120);
formatter.printHelp(LookupPostingsCompressed.class.getName(), options);
ToolRunner.printGenericCommandUsage(System.out);
System.exit(-1);
}
String indexPath = cmdline.getOptionValue(INDEX);
String collectionPath = cmdline.getOptionValue(COLLECTION);
if (collectionPath.endsWith(".gz")) {
System.out.println("gzipped collection is not seekable: use compressed version!");
System.exit(-1);
}
Configuration config = new Configuration();
FileSystem fs = FileSystem.get(config);
MapFile.Reader reader = new MapFile.Reader(new Path(indexPath + "/part-r-00000"), config);
FSDataInputStream collection = fs.open(new Path(collectionPath));
BufferedReader d = new BufferedReader(new InputStreamReader(collection));
Text key = new Text();
ArrayListWritable<PairOfInts> postings;
BytesWritable bytesValue = new BytesWritable();
System.out.println("Looking up postings for the term \"starcross'd\"");
key.set("starcross'd");
reader.get(key, bytesValue);
postings = deserializePosting(bytesValue);
// ArrayListWritable<PairOfVInts> postings = value;
for (PairOfInts pair : postings) {
System.out.println(pair);
collection.seek(pair.getLeftElement());
System.out.println(d.readLine());
}
bytesValue = new BytesWritable();
key.set("gold");
reader.get(key, bytesValue);
postings = deserializePosting(bytesValue);
System.out.println(
"Complete postings list for 'gold': (" + postings.size() + ", " + postings + ")");
Int2IntFrequencyDistribution goldHist = new Int2IntFrequencyDistributionEntry();
// postings = value;
for (PairOfInts pair : postings) {
goldHist.increment(pair.getRightElement());
}
System.out.println("histogram of tf values for gold");
for (PairOfInts pair : goldHist) {
System.out.println(pair.getLeftElement() + "\t" + pair.getRightElement());
}
bytesValue = new BytesWritable();
key.set("silver");
reader.get(key, bytesValue);
postings = deserializePosting(bytesValue);
System.out.println(
"Complete postings list for 'silver': (" + postings.size() + ", " + postings + ")");
Int2IntFrequencyDistribution silverHist = new Int2IntFrequencyDistributionEntry();
// postings = value;
for (PairOfInts pair : postings) {
silverHist.increment(pair.getRightElement());
}
System.out.println("histogram of tf values for silver");
for (PairOfInts pair : silverHist) {
System.out.println(pair.getLeftElement() + "\t" + pair.getRightElement());
}
bytesValue = new BytesWritable();
key.set("bronze");
Writable w = reader.get(key, bytesValue);
if (w == null) {
System.out.println("the term bronze does not appear in the collection");
}
collection.close();
reader.close();
return 0;
}